QLineEdit::text() misleads the user

#include <QApplication>

#include <QHBoxLayout>

#include <QWidget>
#include <QLineEdit>
#include <QPushButton>


#include <QtDebug>


class Form: public QWidget
{
    Q_OBJECT
public:

    Form(QWidget* parent=0):
        QWidget(parent),
        _line_edit(new QLineEdit(this)),
        _push_button(new QPushButton("check", this))
    {
        new QHBoxLayout(this);

        layout()->addWidget(_line_edit);
        layout()->addWidget(_push_button);

        _line_edit->setInputMask("\\0\\xHHHH;0");

        connect(_push_button, SIGNAL(clicked(bool)), this, SLOT(check()));
    }

private slots:

    void check()
    {
        qDebug()
            << "text():" << _line_edit->text()
            << "displayText():" << _line_edit->displayText();
    }

private:
    QLineEdit* _line_edit;
    QPushButton* _push_button;
};


int main(int argc, char* argv[])
{
    QApplication app(argc, argv);

    Form form;

    form.show();

    return app.exec();
}


#include "main.moc"